Jeff: my recollection from the mother i worked with who had to have scan with radioactive iodine was that milk could be scanned in lab to see if it is o.k.... mother i worked with did pump and dump..twice...... there are choices of iodines and each has a differenvt haldf life.....hopefully dr. h will step in and answer you...his book discusses it on page 182. he reccomends use of technetium 99m instead as it is only present from 15 hours to 3 days...again one must pump and dump... patricia